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BRISTOL AVON RIVERS TRUST
"A Clear Future for our River"

Harriet Alvis

What is a drain misconnection – how do they threaten our rivers?

Misconnected pipes and drains are a major threat to UK rivers and seas – plumbing misconnections can contribute towards pollution so it is important to be aware of what to look out for. Throughout the UK there are thousands of homes with misconnected drains, which create large problem for maintaining clean rivers and healthy wildlife. So what is a drain misconnection and why do they affect our rivers?


What is a drain or pipe misconnection?

Usually, there are two sewers within your house – a wastewater sewer, where drainage from your bathroom appliances, toilets and washing machines will go to be treated at a wastewater treatment plant. Surface water, such as rainwater and roof and ground runoffs will head to a river or stream.

If the two pipes become misconnected, dirty water from your toilet or shower could get released into a river before being treated. River pollution then occurs when the wastewater from your appliances (washing machines, sinks and dishwashers are included) drains into the wrong sewers, leading it into streams and rivers. As well as this, the clean water pipes can become misconnected – this can overload the wastewater sewer and lead to flooding. This is why it’s so important to check your drain pipes are not misconnected, avoiding any nasty sewage problems or hefty fines form the council later on (you could be fined up to £50,000, however, this is rare).

How does this damage the environment?
Misconnected drains cause big risks for the environment as well as public health. Marine life can become contaminated from harmful bacteria and chemicals such as faeces and cosmetic items like shampoo. Other products such as bleach and body wash are particularly dangerous to the environment and wildlife as they contain extremely harmful chemicals. Furthermore, those who consume fish are at risk from all the chemicals which have polluted the seas.


How can I look after rivers?

Drain misconnections are a big problem for rivers and seas throughout the country, but misconnections aren’t the only threat to our rivers – flushing items like wet wipes and cotton buds can also be dangerous, even if they state they are ‘flushable’ on the packet. Flushed items can end up in our rivers through misconnections and being small enough to by-pass filtering systems. Research by UKDN Waterflow has shown that most commonly flushed items contain some form of plastic, which can take 500 years or more to biodegrade in a river or marine environment. Therefore, it’s important to only ever flush the 3 P’s – pee, poo and paper. Any other household items or litter should be discarded in the bin.

Wet wipes blocking a pipe – this will cause sewage to back up and overflow into our roads and rivers

Objects not meant for flushing can clog drains and rivers, which can result in flooding. If you want to find out more about drain misconnections and how to identify them, see the recent whitepaper by drainage and wastewater management company – UKDN.

We have reached 60 Riverfly monitors!

We have reached 60 Riverfly Partnership monitors! These volunteers each sample their site once a month, monitoring invertebrates as indicators of water quality. They help us to gain a long term dataset on the health of rivers, as well as identifying pollution incidents to enable response by the Environment Agency.

Click here to find out more about our Riverfly monitoring.

A massive thank you to all our dedicated volunteers! If you are interested in being trained, please get in touch with jess@bristolavonriverstrust.org

We’ve raised one million pounds!

BART are really proud to announce that we have reached the £1 million mark for lifetime funds raised for river restoration and education work! (Plus a huge amount more bought in from partners in joint projects).

From humble beginnings six years ago with a few anglers, saddened at the decline of the Bristol Avon and it’s tributaries, we’ve developed a small but strong team delivering a huge range of projects around the catchment.

We’ve only started scratching at the surface and we have a huge amount left to do, but here’s to delivering the next millions worth of improvements!

BART electrofishing surveys

BART are pleased to announce that we now own our own set of electrofishing kit. BART has been conducting electrofishing surveys for some time with partners, however we have now been able to raise sufficient funds for our own equipment.

Electrofishing is a fish surveying technique combining a mixture of electrical current with a known water conductivity to temporarily stun fish in order to measure and document the population and community fish statistics at a freshwater location. BART ensures that all members of their electrofishing team have adequate training and experiential learning to ensure that fish receive good animal husbandry and are returned to the watercourse in good health with zero impact upon the population as a result of the survey.

BART electrofishing surveys

We hope to use this around the catchment to monitor fish populations to determine sites in need of improvement works and also to follow the success of future restoration works. We have already been out to survey the Norton Brook to guide future restoration plans there, and were pleased to find a good number of juvenile trout.

A juvenile trout from the Norton Brook, Bath

2019 Bristol Avon Waterblitz – the results!

Thank you to all of our 424 wonderful volunteers for your efforts in monitoring for us this year. You can find out the results of the 2019 Waterblitz below!

You can also explore the data further on the interactive map.

What do the results show?

What do these results mean for our freshwater environments?

Elements such as phosphates and nitrates occur naturally in freshwater and are nutrients for plants and important for wildlife. However, at unnaturally high levels they are pollutants, impacting the freshwater ecosystem in detrimental ways. Excess nutrients cause algae, fungi, bacteria and some tolerant water plants to grow more rapidly and become more abundant than they would naturally. The consequences of this are that intolerant species are smothered, outcompeted or directly poisoned resulting in many species becoming rarer. Toxic algal blooms harm aquatic invertebrates and fish by reducing the amount of oxygen in the water and can lead to increased costs of drinking water treatment downstream. In the United Kingdom around 90% of lowland surface freshwaters like rivers, streams and ponds have ecologically damaging levels of either nitrogen, phosphorus or both (Biggs et al. 2014).

The data collected during the 2019 WaterBlitz shows that pollutant levels are high in many parts of the Bristol Avon catchment and have either stayed consistently high or increased in the past 3 years. It demonstrates a greater need to address the causes and decreasing the movement of pollutants into local watercourses, particularly though sewage effluent, fertiliser run-off and from urban surfaces. The WaterBlitz data you collected is being used to identify pollution hotspots where action needs to be taken.

How can you help?

  • Volunteer with your local Rivers Trust or community group. Get involved in river cleans, restoration projects and community initiatives to decrease pollution.
  • Reduce pollution by only flushing the 3 P’s, avoid pouring fats and oils down the sink, compost food waste and limit the use of household detergents and garden fertilisers.
  • Collect data during future WaterBlitz. Look out for- and report- pollution incidents when out for a walk (24/7 to the Environment Agency on 0800 807060) and get involved in citizen science events.

These above results are available as a PDF which is available on request from harriet@bristolavonriverstrust.org